1. Field of Invention
This invention relates to optical imaging and detection and, in particular, to an apparatus for authenticating standardized documents.
2. Description of Related Art
Documents of a standardized size include passports, birth certificates, driver's licences, identity cards, health care cards, bank notes, and other government issued documents. Standards exist to ensure that such documents are of a similar size. For example, a standard passport is typically about 90×125 mm (or 3.5×4.9 inches), although the standard size for a German passport is slightly larger than for passports of other countries.
Various devices have been developed to detect or authenticate standardized documents. For example, an apparatus and method for verifying the authenticity of a value item, which may include a standardized document, is disclosed in the international publication No. WO 2006/021083 published on 2 Mar. 2006, naming TALWERDI et al. as inventors, and entitled APPARATUS AND METHOD FOR SECURE IDENTIFICATION OF SECURITY FEATURES IN VALUE ITEMS, which is incorporated herein by reference for all purposes. Also, an apparatus and method for detecting an item, which may include a standardized document, is disclosed in the international publication No. WO 2008/034250 published on 27 Mar. 2008, naming TALWERDI as inventor, and entitled APPARATUS AND METHOD FOR SECURE DETECTION OF AN ITEM AND A METHOD OF SECURING ACCESS TO INFORMATION ASSOCIATED WITH THE ITEM, which is incorporated herein by reference for all purposes.
Some embodiments of these detection devices include a housing dimensioned to receive an item such as a document, the housing having a support plate for supporting the standardized document being detected or authenticated. Within the housing are sources for producing electromagnetic radiation and an imaging device for producing an image of the document. Detection occurs by the sources generating electromagnetic radiation incident upon the document and the imaging device receiving electromagnetic radiation that has reflected from the document.
There is the known problem of undesirable reflections occurring within the housing that result in the imaging device imaging objects other than the desired document.
Some conventional imaging devices use arrangements of optical lenses and filters to avoid undesirable reflections. However, the use of optical lenses or filters increases complexity and manufacturing costs.
Some conventional devices for authenticating standardized documents scan along only one line of the standardized document at a time. However, such conventional devices require the standardized document, or corresponding scanning components, to travel along a path while being scanned, thereby increasing the time required to image an entire standardized document.
It is desirable for a device capable of detecting or authenticating a standardized document to have a length and width comparable to that of the largest standardized document being detected or authenticated.